Extended opening die casting machine



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Jan. 27, 1970 E, po 3,491,826

EXTENDED OPENING DIE CASTING MACHINE Filed July 15, 1966 IN VENTOR.

Z3 33 4 3 RICHARD E.PUTT5'.

ATTZYE.

United States Patent Oflice 3,491,826 Patented Jan. 27, 1970 3,491,826 EXTENDED OPENING DIE CASTING MACHINE Richard E. Potts, Toledo, Ohio, assignor to National Lead Company, New York, N.Y., a corporation of New Jersey Filed July 15, 1966, Ser. No. 565,583 Int. Cl. B22d 17/00 US. Cl. 164303 7 Claims ABSTRACT OF THE DISCLOSURE An extended opening die casting machine for use in producing elongated die castings. The machine has a longitudinal base which mounts opposed front and back plates. A sliding plate and an auxiliary plate are positioned between the front and back plates. A crab mechanism is mounted between the back plate and the auxiliary plate. Right parallelepiped compression blocks are removably mounted between the auxiliary plate and the sliding plate. The compression blocks are moved into and out of blocking position by displacement cylinders and are of an axial length sufficient to provide an extended die opening.

This invention relates to die-casting machines and more particularly, to a die-casting machine having an extended die receiving opening.

While the present invention may be used in connection with a die-casting machine of the submerged-plunger type, it is more commonly used on a high pressure cold-chamber injection type machine. Machines of the later type are used for the die casting of higher melting point alloys, such as aluminum, magnesium, and brass.

In cold-chamber die casting machines injection pressures of 10,000 psi. and higher are not uncommon. When working with high pressures it is necessary that the opposed die halves be held in position under high locking pressures while the shot is being made.

Because of the overall increase in machining labor costs, many industries are specifying larger and more complex die castings. Prior art die casting machines are not capable of successfully producing extremely long die castings of high temperature alloys. A die casting that is long or deep in the axial direction of the machine, which is the axial direction of the shot sleeve, requires a die casting machine with an extended opening to properly eject the completed die casting. Because of the high pressures and resultant forces involved, it is not satisfactory to merely extend the length of the toggle mechanisms in prior art die casting machines. If the length to width ratio of the toggle links is substantially increased such links fail, when placed under the high compression forces resulting from the die locking operation. Furthermore, it is not possible merely to increase the size of prior art toggle linkages because not enough clearance space is available in such prior art apparatus to handle the larger linkages.

It is the primary object of the present invention to provide an improved die casting machine having an extended opening to receive elongated or deep dies.

It is another object of the present invention to provide an improved die casting machine having an improved locking mechanim which is suitable for holding the two halves of a die together under high locking pressures.

Further objects will become apparent from the following specification and drawings in which:

FIG. 1 is a side elevational view of an improved die casting machine, according to the present invention;

FIG. 2 is a side elevational view, similar to FIG. 1, drawn on an enlarged scale, and showing portions of the die casting machine in vertical cross section;

FIG. 3 is a side elevational view, similar to FIG. 2, showing the die casting machine, according to the present invention, in a locked position; and

FIG. 4 is a vertical sectional view, with parts broken away, taken along the line 44 of FIG. 2.

Briefly, the invention relates to an extended opening die casting machine having the conventional longitudinally extending base on which a front plate is fixedly mounted to carry the cover die. A back plate is spaced from the front plate on the base and a plurality of guide bars extend between and are connected to the front plate and the back plate. A sliding plate on which the ejector die is mounted is usually moved towards and away from the front plate by a crab mechanism. The present invention interposes an auxiliary plate between the back plate and the sliding plate, and the crab mechanism moves the auxiliary plate forward and back. A separate cylinder means is provided to impart relative movement between the auxiliary plate and the die carrying sliding plate to supplement the longitudinal stroke of the crab mechanism, and blocking means are moved into position between the relatively movable sliding plate and auxiliary plate so that the forces tending to open the machine during a die casting operation are taken through the blocking means, the auxiliary plate and the crab mechanism. These forces then appear as tension forces in the guide bars which join the front and back plates in the usual manner.

. When the die halves are in open position the crab mechanism is retracted, the blocking means withdrawn, and the separate cylinder means has moved the sliding plate and auxiliary plate into close juxtaposition to give a maximum die opening. When the die halves are in closed position the crab mechanism is extended, the sliding plate and auxiliary plate are moved apart and the blocking means are interposed therebetween. In this closed position the machine is capable of withstanding the full die casting pressures. I

Referring to FIG. 1, an extended opening die casting machine, according to the present invention, is indicated by the reference number 10. The die casting machine 10 comprises a longitudinally extending base 11 having the usual upper guide tracks.

A front plate 13 is fixedly mounted to the base 11 and has means on an inner surface 14 for mounting a cover die 15.

The die casting machine 10, illustrated in the drawings, is a cold-chamber machine and includes shot mechanism generally indicated -by the reference number 16 (see FIG. 1). The shot mechanism 16 comprises a pedestal 17, which is mounted on the base 11, a hydraulic shot cylinder 18, and a shot sleeve 19 which is in communication with the interior of the die halves, through an opening in the cover die 15 (see FIG. 3), in a manner well known in the art.

A back plate 21 is spaced from the front plate 13 and is positioned on the guide tracks 12 of the base 11. In the present embodiment the plate 21 is provided with rollers 22 which engage and ride upon the tracks 12. A plurality of heavy duty guide bars 23 extend between and are connected to the front plate 13 and the back plate 21 and the distance setting between the front and back plates is adjustable by guide bar nuts 24 as is the usual practice.

A sliding plate 25, having rollers 26, in engagement with tracks 12 is positioned between the front plate 13 and the back plate 21'. The sliding plate 25 has a plurality of openings 27 through which the guide bars 23 extend.

Means are provided on a surface 28 of the sliding plate 25 for mounting an ejector die 29 in an opposed and complementary relationship to the cover die 15, which is mounted on the front plate 13.

An auxiliary plate 31, having rollers 32, is mounted for longitudinal movement along the tracks 12 of the base 11.

3 The auxiliary plate 31 is positioned between the sliding plate 25 and the back plate 21 and has a plurality of openings 33 through which the guide bars 23 extend (see FIG. 4).

I Closingmeans are provided for moving the auxiliary plate 31 between a retracted position, shown in FIG. 2, and an extended position, shown in FIG. 3. When in the extended position shown in FIG. 3, the closing means is locked and the auxiliary plate 31 and its supporting structure resists die casting forces which are transmitted through the die casting machine to the auxiliary plate 31. In the present embodiment, the closing means comprises a conventional crab mechanism generally indicated by the reference numeral 34. The crab mechanism 34 includes a closing cylinder 35 carried by the back plate 21. The cylinder 35 has a rod 36 connected to a cross head 37 (see FIG. 3). The cross head 37 is mounted for movement on a pair of cross head guide bars 38. A plurality of toggle links 39 extend between and are pivotally connected to the cross head 37, the back plate 21, and the auxiliary plate 31, respectively.

Referring to FIG. 2, when it is desired to move the auxiliary plate 31 from the retracted position to the extended position (shown in FIG. 3) the closing cylinder 35 is actuated. The rod 36 and the cross head 37 move to the right (see FIG. 2) until the toggle links 39 are in the locked position shown in FIG. 3.

Referring in particular to FIG. 2, cylinder means are provided for moving the sliding plate 25 between a retracted position (shown in FIG. 1) and an extended position (shown in FIG. 3) wherein the sliding plate 25 and its supporting structure are in a closed position to receive the forces generated by the die casting operation. In the present embodiment, the cylinder means includes a cylinder 41 which is connected to and carried by the auxiliary plate 31. The cylinder 41 has a rod 42 which is connected to the sliding plate 25. In the present embodiment, the sliding plate 25 has a striking surface 43 adjacent the auxiliary plate 31.

Blocking means including a plurality of compression blocks 44 are interposed between the auxiliary plate 31 and the striking surface 43 of the sliding plate 25 when the sliding plate 25 is in the extended position shown in FIG. 3. Each of the compression blocks 44 is a right parallelepiped in shape, having opposed parallel surfaces which lie in planes perpendicular to the longitudinal axis of the base 11. The opposed parallel surfaces of the compression blocks 44 engage complementary surfaces on the auxiliary plate 31 and the sliding plate 25. The blocks 44 have a length in the axial direction of the machine sufficient to provide an extended die opening (see FIG. 1).

Displacement means are provided for moving the compression blocks 44 between a rest position (shown in FIG. 1) which is exterior of the normal path of movement of the sliding plate 25 and a blockingposition (shown in FIG. 3). When the compression blocks 44 are in their blocking position they are in force transmitting relationship with the auxiliary plate 31 and the striking surface 43 ,of the sliding plate 25. In the present embodiment, the displacement means comprises cylinders 45 having rods 46 which are operably connected to the compression blocks 44. The cylinders 45 are supported by brackets 47 which are mounted on and carried by the auxiliary plate 31*. It should be noted that other types of displacement means may be utilized and still fall within the scope of the present invention.

. In atypical operation of the die casting machine 10,

the diehalves 1S and 29 are secured to the front plate 13 and to the sliding plate 25. The machine is adjusted tothe proper closing position by setting nuts 24 in the guide rods 23. Thereafter, the operation will be described with the parts standing in the die open position, assuming 4 I v i is actuated and the cylinder rod 42 moves to the right (as shown in FIG. 1) thereby moving the sliding plate 25 to its extended position. When the sliding plate 25 has reached its extended position, the displacement means cylinders 45 are actuated and the compression blocks 44 move inwardly to their blocking position between the auxiliary plate 31 and the striking surface 43 of the sliding plate 25. As will be seen in FIG. 2, when the die casting machine 10 has reached this position, the ejector die 29 has begun its mating engagement with the cover die 15.

Next, the closing cylinder 35 of the crab mechanism 34 is actuated and the cylinder rod 36, which carries the cross head 37, moves to the right (see FIG. 3) moving thetoggle links 39 to the locked position shown in FIG. 3, wherein the auxiliary plate 31 has moved from its retracted position to its extended position.

When both the sliding plate 25 and the auxiliary plate 31 are in the closed or extended position, shown in FIG. 3, the ejector die 29 and the cover die 15 are in a complementary relationship and are ready for the casting shot. At this time, metal is injected from the shot sleeve 19, in the normal manner, and the die casting machine and its component parts are placed under high pressures. This force is transmitted rearwardly through the sliding plate 25, the compression blocks 44, the auxiliary plate 31, aligned ones of the toggle links 39, the back plate 21, and to the massive guide bars 23 movement of which is resisted by the front plate 13 and the machine frame.

After a part has been cast, the die casting machine 10 is opened from the position shown in FIG. 3 to eject the cast part. At this time, the closing cylinder 35 of the crab mechanism 34 is actuated and the cylinder rod 36 carrying the cross head 37 is moved to the left (see FIG. 2) until the auxiliary plate 31 has reached the retracted position shown in FIG. 2. At this time, the ejector die 29 has not completely cleared the cover die 15 and the cast part still cannot be removed.

Next, the cylinders 45 are actuated and the compression blocks 44 are moved outwardly until they reach the rest position shown in FIG. 1. It has been found that the retraction movement of the toggle links 39 creates enough drag force on the surrounding components to free the compression blocks 44 from their locked position between the auxiliary plate 31 and the striking surface 43 of the sliding plate 25, thereby permitting the compression blocks 44 to move outwardly easily.

After the compression blocks 44 have been displaced, the cylinder 41 carried by the auxiliary plate 31 is actuated and the sliding plate 25 is moved from its extended position, shown in *FIG. 2, to its retracted position, shown in FIG. 1. At this time, the ejector die 29 has cleared the cover die 15 and the cast part maybe ejected in the usual manner.

While the present invention has been disclosed in connection with a specific arrangement and disposition of the parts, it shouldbe expressly understood that numerous modifications and changes may be made without departing from the scope of the appended claims.

I claim: Y

1. .An extended opening die casting machine, comprising, a longitudinally extending base, a front plate fixedly mounted to said base, means on said front plate for mounting a cover die, aback plate spaced from said front plate and positioned on said base, a plurality of guide bars extending between and connected to said front plate and said back plate, a sliding plate positioned between said front plate and said back plate mounted for movement on said base, means on said sliding plate for mounting an ejector die'in opposed and complementary relationship to a cover die mounted on said front plate, an auxiliary plate positioned between said sliding plate and said back plate mounted for movement on said base, blocking means including at least two compression blocks remova'bly mounted between said auxiliary plate and said sliding plate, each of said compression blocks having opposed parallel surfaces which lie in planes perpendicular to said longitudinally extending base, such compression block surfaces engaging complementary surfaces on said auxiliary plate and said sliding plate respectively, each of said compression blocks having a length sufficient to provide an extended die opening, displacement means for moving said compression blocks between a rest position exterior of the normal path of movement of said sliding plate and a blocking position wherein said compression blocks are between said sliding plate and said auxiliary plate and are within the normal path of movement of said sliding plate, and closing means for moving said auxiliary plate between a retracted position adjacent said back plate and an extended casting position, said closing means including a crab mechanism having toggle linkage extending between said back plate and said auxiliary plate.

2. An extended opening die casting machine according to claim 1, wherein said closing means comprises a crab mechanism having toggle links extending between said 'back plate and said auxiilary plate and at least one cylinder operatively connected to said toggle links and to said back plate.

3. An extended opening die casting machine accord ing to claim 1, wherein said displacement means comprises at least one cylinder operatively connected to each of said compression blocks.

4. An extended opening die casting machine, according to claim 3, wherein said displacement means cylinders are carried by said auxiliary plate.

5. An extended opening die casting machine, according to claim 2, including at least one cylinder operatively connected between said auxiliary plate and said sliding plate.

6. In a die casting machine having a base, a front plate fixed to said base, a back plate spaced from said front plate, a plurality of guide bars extending between and connected to said front plate and said back plate, a sliding plate positioned between said front plate and said back plate and mounted for movement on said base, and means on said front plate and on said sliding plate for mounting a cover die and an ejector die in complementary positions, the invention comprising, an auxiliary plate positioned between said sliding plate and said back plate and mounted for movement on said base, closing means including a crab mechanism having toggle linkage extending between said back plate and said auxiliary plate, blocking means including at least two compression blocks removably mounted between said auxiliary plate and said sliding plate, each of said compression blocks having opposed parallel surfaces which lie in planes perpendicular to the longtudinal axis of said base, such compression block surfaces engaging complementary surfaces on said auxiliary plate and said sliding plate respectively, each of said compression blocks having a length suflicient to provide an extended die opening and displacement means for moving said compression blocks between a rest position exterior of the normal path of movement of said sliding plate and a blocking position wherein said compression blocks are between said sliding plate and said auxiliary plate and are within the normal path of movement of said sliding plate.

'7. Die casting apparatus, according to claim 6, said displacement means comprising cylinders carried by said auxiliary plate, each of said cylinders being operatively connected to a respective one of said compression blocks.

References Cited UNITED STATES PATENTS 2,848,771 8/1958 Eggenberger 164343 X 3,161,918 12/1964 Zearbaugh 164--343 X 3,263,277 8/ 1966 Ohlendorf et a1. 164343 X 2,744,304 5/1956 Kaul 164303 3,310,840 3/1967 Aoki 1816 X FOREIGN PATENTS 202,311 6/ 1956 Australia.

995,899 6/1965 Great Britain.

1 12,706 9/1962 Germany.

661,136 5/ 1967 Netherlands.

I. SPENCER OVERHOLSER, Primary Examiner U.S. Cl. X.R. 

